Conventionally, a clean room of partial laminar flow type is known as a clean room in which ultra high cleanliness is maintained inside the room.
In the clean room of this type, outlet ports of air supply ducts are provided to almost the entire surface of the ceiling of the room. Air with ultra high cleanliness is blown off from these outlet ports into the room, flows downward toward the floor of the room in one direction in an almost laminar state, is exhausted into air inlet ports provided to almost the entire surface of the floor, and is circulated to the air outlet ports. Generally, the floor is a porous one made of a grating or a punching metal, and a number of pores of this porous floor serve as air inlet ports. In addition, the air outlet ports are provided with a high performance dust filter such as a ULPA filter.
Since the above conventional clean room blows off air from the entire surface of the ceiling, it requires a large absolute supply amount of air, resulting in increase in a running cost for a blower or the like, and hence in a high energy consumption type clean room. In addition, since the air blown off from the ceiling flows toward the floor only in one direction, dust generated in a passage or the like may be undesirably diffused by movement of a worker into a region requiring ultra high cleanliness, e.g., an installation region of a semiconductor manufacturing system in the clean room.
Accordingly, it is an object of the present invention to provide an energy-saving clean room.
It is another object of the present invention to provide a clean room wherein the amount of dust entering the installation region of the semiconductor manufacturing system is reduced to increase the yield of products.
It is still another object of the present invention to provide a clean room wherein vibrations of a floor of a passage are suppressed when a worker walks along the passage so that the vibrations are not easily transmitted to the semiconductor manufacturing system or the like.
It is still another object of the present invention to provide a clean room wherein maintenance of the semiconductor manufacturing system or the like installed inside the room or carrying in and out of a material with respect to the installation region can be easily performed.